From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 594E8C10DCE for ; Sun, 15 Mar 2020 08:19:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23D0120578 for ; Sun, 15 Mar 2020 08:19:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ay+2V4sH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727811AbgCOIS7 (ORCPT ); Sun, 15 Mar 2020 04:18:59 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:55324 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727756AbgCOIS7 (ORCPT ); Sun, 15 Mar 2020 04:18:59 -0400 Received: by mail-wm1-f65.google.com with SMTP id 6so14278607wmi.5 for ; Sun, 15 Mar 2020 01:18:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:reply-to:references:mime-version :content-disposition:in-reply-to:user-agent; bh=bIdO2DD9SS58shQaI+L75kVmCFLCfvHKiwc1M49jAT0=; b=ay+2V4sH5dFVbqHqfzxJ9qOQZ2y3OLeLccxpD0pfwtd9I+pBtYkK0mvCKX8x10Hdbe H7euB4kz2RwOyD2+mNxIl9ZWMXaNnwzjlAB910zZColpVhTHkKA+md8TYVkiY0V3QsOg I7b7BnYV4i5nsvi+qbiWFczXjFJPutx0H3AB41/Ah/XFJ8yKzx+fHV5yR85t1sEL8Fuu xeNco7xZ19VujSR1l980NIFyzw4FozakcEcNYj868N2UrJCOG6kZUjxqsyP2mAffcXbc V2J8iwPIuY7KkDwnXtGNo6frZH4rRcDzZyZ3Oo0BRauk3mZO/1LaEcYxbTXV1uREDBjf G4Eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:reply-to :references:mime-version:content-disposition:in-reply-to:user-agent; bh=bIdO2DD9SS58shQaI+L75kVmCFLCfvHKiwc1M49jAT0=; b=KeivFb3seFMUHSnPbiYJTiCfBdBtfm1wVFC10Nk+80H9oSqQgwSkTR8wjOcjg44+6N qapCMnuw1UIa0HWiGuy/AS16yc3FvFXukeylPXDZuV/qOVyu6dZSF8mrJoNJSiVDNFG5 XvnbxBdGVgWADNpeqtqk17N7Wod/cLN6+3gFvHeN+FgaBN+At3iIZk+0fuLkZGjYzrzl i5tbeNynNe7RkyMuwhQGKcQ7RCR6XXFT1mNZdFf7VBEBeEtnV7/E1av9Ax2zmmqPnZRb O4oRh8YX7o69QxpRf9MqHg1zwzoKs5kImFG6ilaXPA/QEQSIw6tbLfBijaKSfsoKYwyP 6Ucg== X-Gm-Message-State: ANhLgQ0EY42CEreSjurj4b6H0mpTZC86Fywe2mKqxDqwXyGWXPBnGJo6 CFmjHM2YKJyjCB9H15+LVys= X-Google-Smtp-Source: ADFU+vumiWAhOGnJquqo1N4StHWr1Li6Q/nrOllp5GIISU6iTtGORSshLBqJc7b7YvGZKUIa8CXUjQ== X-Received: by 2002:a1c:b144:: with SMTP id a65mr16208631wmf.54.1584260336166; Sun, 15 Mar 2020 01:18:56 -0700 (PDT) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id b4sm1349519wmj.12.2020.03.15.01.18.55 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 15 Mar 2020 01:18:55 -0700 (PDT) Date: Sun, 15 Mar 2020 08:18:54 +0000 From: Wei Yang To: "Huang, Ying" Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dave Hansen , David Hildenbrand , Mel Gorman , Vlastimil Babka , Zi Yan , Michal Hocko , Peter Zijlstra , Minchan Kim , Johannes Weiner , Hugh Dickins Subject: Re: [RFC 2/3] mm: Add a new page flag PageLayzyFree() for MADV_FREE Message-ID: <20200315081854.rcqlmfckeqrh7fbt@master> Reply-To: Wei Yang References: <20200228033819.3857058-1-ying.huang@intel.com> <20200228033819.3857058-3-ying.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200228033819.3857058-3-ying.huang@intel.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 28, 2020 at 11:38:18AM +0800, Huang, Ying wrote: >From: Huang Ying > >Now !PageSwapBacked() is used as the flag for the pages freed lazily >via MADV_FREE. This isn't obvious enough. So Dave suggested to add a >new page flag for that to improve the code readability. I am confused with the usage of PageSwapBacked(). Previously I thought this flag means the page is swapin, set in swapin_readahead(). While I found page_add_new_anon_rmap() would set it too. This means every anon page would carry this flag. Then what is this flag means? -- Wei Yang Help you, Help me